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Why the diet industry is increasingly seen as part of the obesity problem

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The diet industry may be the biggest rort in history. It’s worth an estimated US$175 billion ($250 billion) a year, but the amount is even more staggering when you consider that diets rarely achieve sustainable weight loss.

It is important to point out that it is the diet that fails the dieter, not vice versa. The growing realisation that weight-loss diets aren’t a sustainable solution has led the Royal Australasian College of Physicians to shift its focus from weight-loss diets in a position statement on obesity.

“Treatment goals should focus on encouraging healthy, nutritious diets, regular physical activity and adequate sleep to optimise health, including mental health. These goals are valid at any weight,” says Boyd Swinburn, professor of population nutrition and global health at the University of Auckland, who co-wrote the position statement.

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Swinburn says physicians have paid a lot of attention to evidence that shows if you lose 5-10% of your weight, you will be healthier and reduce metabolic risk factors such as impaired blood glucose and high blood pressure, and the risk of diabetes. “But I don’t think we paid enough attention to the evidence that most people who go on a diet actually end up back at the weight they were or even higher.”

That weight regain comes at a cost, says Swinburn. There is a sense of failure at having unsuccessfully gone on one or multiple diets. And we now know that a metabolic resetting promotes weight gain after a diet.

Indeed, dieting may be one of the most reliable predictors of becoming more overweight.

A 2012 study published in the International Journal of Obesity assessed dieting habits in more than 2000 sets of twins, including those genetically identical. It found those individuals who dieted were two to three times more likely to become overweight than their non-dieting twin.

If dieting messes up our metabolism and causes weight gain, is our diet culture actually contributing to the obesity epidemic?

“I think that suspicion must be there,” says Swinburn. However, without clear evidence or scientific modelling to support that view, the best Swinburn can offer is “that’s possibly the case”.

The college of physicians is now advising health professionals to focus on optimising health at any weight, to balance the potential benefits and risks of dieting for patients and to end weight bias and stigmatisation.

Weight bias is defined as holding a negative attitude towards a person because of their weight.

In a 2016 study published in Obesity Science & Practice, 201 accredited practising Australian dieticians were assessed for fat phobia. Although their scores indicated only mild fat phobia, a greater degree of bias was noted in a clinical situation.

The dieticians were presented with one of two clients who had identical case notes about their health, the only difference being that one client was obese. The dieticians presented with the obese client assessed them as having significantly poorer health and were more likely to provide unsolicited weight management recommendations.

They also rated the obese client as “less receptive, less motivated and as having a lower ability to understand and sustain recommendations”.

Weight bias has been reported in other practitioner groups, too. One study found 45% of physicians held negative views about patients affected by obesity.

Weight bias causes real harm to people with obesity; it negatively affects their employment opportunities, personal relationships and educational attainment. It may lead to reduced dietary control, and increased energy intake in overweight women. What’s more, many people with obesity internalise negative messages and are at higher risk of developing depression.

The college is planning to include awareness and management of weight bias in its training programmes for physicians, says Swinburn, but weight bias is widespread in society.

“The automatic assumption is that people with obesity don’t have willpower – they’re lazy and stupid and so on.

“That’s a prejudgment of people that is unwarranted and we need to increase the awareness of that.”

This article was first published in the June 16, 2018 issue of the New Zealand Listener.